Method of forming score lines on blank, method of manufacturing package using same, and package

ABSTRACT

A blank forming step for forming a sheet-shaped resin blank able to be formed into a box by folding and bending, and a score line forming step of forming score lines in score line forming areas of the blank which are to be bent to form outer edges of the box, to extend in the direction in which the outer edges should extend. In the score line forming step, the score lines are formed in a manner causing grooves to be produced on the back side of each score line forming area, along the score lines, through plastic deformation. The blank therefore does not undergo tensile stress pulling on the blank to either side of each groove, and thus, does not undergo warping as a whole. The blank thus retains its sheet shape and can be steadily supplied to a packaging machine.

TECHNICAL FIELD

The present invention relates to a method of forming score lines on a blank, a method of manufacturing a package using same, and a package.

background art

Generally, packages of this type are called hinged-lid packages. The hinged-lid package is cuboidal in shape and has four longitudinal angular edges. The package with angular edges does not fit comfortably in the hand of a user who holds the package. The package with rounded edges in place of angular edges is therefore preferable. A blank (plastic sheet) for forming a package with rounded edges is known (see patent document 1, for example).

According to patent document 1, score lines are formed on the blank by pressing blades against the blank, and the resulting score-lined areas are bent into rounded edges.

The forming of score lines in the manner shown in patent document 1, however, stretches the score-lined surface, so that the blank warps in the manner that the score-lined surface bulges. Such warped blank is not allowed to be supplied to a packaging machine to package items, such as cigarettes, in the blank. If the package is formed using such warped blank, the inner side of each rounded edge, namely the back side of each score-lined area stores the power to return to the original state, so that the whole package is swollen and distorted. Such distorted package is regarded as poor-quality and thus cannot be put on the market.

PRIOR ART DOCUMENT Patent Document

Patent Document 1: JP 2004-98586 A

SUMMARY OF THE INVENTION Problems to be solved by the Invention

The present invention intends to provide a method of forming score lines on a blank in a manner not causing deformation, such as warping, of the whole blank so that the score-lined blank can be steadily supplied to a packaging machine and formed into a package without distortion, and a method of manufacturing a cigarette package with rounded edges using same, and a cigarette package.

Means for Solving the Problems

The present invention provides a method of forming score lines on a blank, comprising steps of:

forming a sheet-shaped resin blank able to be formed into a box by folding, and

forming score lines in score line forming areas of the blank which are to be bent to form outer edges of the box, to extend in a direction in which the outer edges should extend, wherein in the score line forming step, the score lines are formed in a manner causing grooves to be produced on a back side of each score line forming area, along the score lines, through plastic deformation.

Desirably, the box to be formed comprises a box-shaped container open at the top and a box-shaped lid connected to a top edge of the container functioning as a hinge to open and close the container; the blank comprises a main section for forming the container, extending in one direction, and a sub-section for forming the lid, connected to an edge of the main section which is to form the hinge; the main section includes a front main panel, a bottom panel and a rear main panel for forming a front wall, a bottom wall and a rear wall of the container, aligned in the direction and delimited by transverse fold lines, and outer and inner side main flaps for forming an outer and an inner layer of each side wall of the container, connected to either side of the front main panel and of the rear main panel; the sub-section includes a rear sub-panel, a top panel and a front sub-panel for forming a rear wall, a top wall and a front wall of the lid, aligned in the direction and delimited by transverse fold lines, and inner and outer side sub-flaps for forming an inner and an outer layer of each side wall of the lid, connected to either side of the rear sub-panel and of the front sub-panel; and the score line forming areas are provided between the front main panel and the outer side main flap, between the rear main panel and the inner side main flap, between the rear sub-panel and the inner side sub-flap, and between the front sub-panel and the outer side sub-flap, respectively.

Desirably, in the blank forming step, a printed layer for providing information about items to be contained in the box in a manner recognizable from the score line forming area side is formed on a side of the blank opposite to the score line forming area side.

Desirably, the blank is made of polyethylene terephthalate.

The present invention also provides a method of manufacturing a cigarette package with rounded edges using the aforementioned score line forming method, wherein after the score line forming step, the blank is formed into the box by folding and bending the blank with the score-lined surface outside.

The present invention also provides a cigarette package with rounded edges manufactured by the aforementioned cigarette package manufacturing method.

ADVANTAGEOUS EFFECTS OF THE INVENTION

The method according to the present invention comprises a blank forming step of forming a blank able to be formed into a box by folding, and a score line forming step of forming score lines in areas of the blank which are to be bent to form outer edges of the box, to extend in a direction in which the outer edges should extend, and in the score line forming step, the score lines are formed in a manner causing grooves to be produced on a back side of each score line forming area, along the score lines, through plastic deformation. The score lines are thus formed on one side of the blank which is to form the outer surface of the box, and the forming of the score lines on one side of the blank simultaneously and automatically causes the production of grooves on the other side of the blank through plastic deformation. The blank therefore does not undergo tensile stress pulling on the blank to either side of each groove, and thus, does not undergo warping as a whole. Since the blank retains its sheet shape, it can be steadily supplied to a packaging machine. From the blank prevented from warping, a package can be formed without distortion.

When the blank is configured to have a main section and a sub-section so as to be applied to a cigarette package (so-called hinged-lid package), the resulting cigarette package has rounded edges formed by bending the score-lined areas. Such package fits comfortably in the hand.

In the blank forming step, a printed layer is formed on the side of the blank opposite to the score line forming area side, which means that the score lines are not formed directly on the printed layer.

When made of polyethylene terephthalate, the blank is easy to handle and easy to form score lines thereon.

A cigarette package with rounded edges can be produced from the blank having undergone the score line forming step, by bending the blank with the score-lined surface outside, thereby forming the blank into a box, where each score-lined area can be bent into a rounded edge utilizing the score lines. The cigarette package with rounded edges fits comfortably in the hand.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a cigarette package according to the present invention in a closed state.

FIG. 2 is a schematic diagram showing the package shown in FIG. 1, in an open state.

FIG. 3 is a schematic diagram showing a blank to which score lines forming method according to the present invention has been applied.

FIG. 4 is a schematic diagram for explaining the process of forming score lines.

FIG. 5 is a schematic diagram for explaining the process of forming score lines.

FIG. 6 is a schematic diagram showing another blank to which the score lines forming method according to the present invention has been applied.

FIG. 7 is a schematic diagram showing an inner frame to which the score lines forming method according to the present invention has been applied.

MODE FOR CARRYING OUT THE INVENTION

A cigarette package (box) 1 shown in FIG. 1 is, as a whole, cuboidal in shape and covered with a transparent film (not shown). The covering film has a tear tape. The package is partly exposed by opening the covering film along the tear tape. The cigarette package 1 includes a container 2. The container 2 is open at the top. The open top is closed with a lid 6. The lid 6 is connected to the rear top edge of the container which functions as a hinge 4. The lid is therefore able to be rotated on the hinge 4 to open or close the container. More specifically, as seen from FIG. 2, the container 2 has inclined top edges. The container 2 has further a U-shaped inner frame 10. The inner frame 10 is arranged to project from the top of the container 2 to define the top opening 12 of the container 2. The inner frame 10 has an access opening 14 in the front wall thereof. The access opening 14 has an approximately U shape.

The lid 6 is in the shape of a box whose bottom edges define an inclined opening. The lid 6 is designed to close the top opening 12 in the manner that the lid 6 lies over the projecting part of the inner frame 10. In the closed state, the bottom edges of the lid 6 meet the top edges of the container 2. While in common packages, the container has four longitudinal angular edges, the container 2 of the present invention has rounded edges 16 in place of angular edges. In the transverse cross-section of the container 2, each rounded edge 16 shows a circular arc shape. The lid 6 has similar rounded edges 18 corresponding to the rounded edges 16, respectively. As seen from FIG. 1, in the container closed with the lid 6, each rounded edge 16 is in alignment with the corresponding rounded edge 18 so that they constitute a longitudinal edge of the package 1. As will be described later, the inner frame 10 has two rounded edges 24.

To obtain the cigarette package 1 with rounded edges, the present invention provides a manufacturing method described below.

The cigarette package 1 is formed by folding a sheet-shaped blank 3 (see FIG. 3). The blank 3 has transverse fold lines 5 formed to make the blank 3 easy to fold at intended locations. The blank 3 is, in advance, cut into a desired shape so that the blank 3 can be formed into the intended box shape by folding. The blank 3 is formed by a known blank forming process. It is to be noted that in the blank forming step, fold lines for forming the longitudinal edges (referred to as “longitudinal fold lines”) are not formed.

In the present invention, a score line forming step is performed, in which score lines 7 are formed in each score line forming area 8 of the blank 3, which is an area to be folded into a longitudinal edge of the box 1, that is, an area in which normally a longitudinal fold line is formed, to extend in the direction in which the edge should extend. The score lines 7 are formed on that side of the blank which is to form the outer surface of the box 1. In other words, the score lines forming areas 8 are on that side of the blank which is to form the outer side of the box, so that the score lines 7 are formed only on that side of the blank.

In the score line forming step, the forming of the score lines 7 causes grooves 9 (see FIG. 5) to be produced on the back side of each score line forming area, along the score lines 7, through plastic deformation. In other words, although the score lines 7 are formed only on that side of the blank 3 which is to form the outer surface of the box 1 as mentioned above, the forming of the score liens 7 on one side of the blank simultaneously and automatically causes the production of grooves 9 on the other side of the blank through plastic deformation. Such production of the grooves 9 is brought on by using a cutting device 11 as shown in FIG. 4. The cutting device 11 is a rotary die cutter having ten parallel blades 13 at approximately 0.8 mm intervals, for example. The score lines 7 and grooves 9 are formed by pressing each score line forming area 8 with the blades 13. Specifically, score lines 7 are formed on one side of the blank 3 by pressing the score line forming area 8 with the blades 13. During this step, when the blades penetrate to a certain depth, the blank is pulled on to either side of each score line 7 and plastically deformed. Grooves 9 are thus automatically formed on the back side of the score line forming area 8, at positions corresponding to the bottoms 7 a of the score lines 7. The grooves 9 extend along the score lines 7 as mentioned above. More specifically, the grooves 9 develop along the respective score lines 7 in a manner corresponding to the respective score lines 7. The depth D of the score lines 7 is 134.74 μm in the case that the blank is 307.97 μm thick, for example. The blank 3 with the groove 8 produced this way does not undergo tensile stress pulling on the blank 3 to either side of each groove 9, and thus, does not undergo warping as a whole. The blank 3 thus retains its sheet shape, and can be steadily supplied to a packaging machine. From the blank thus prevented from warping, the package 1 can be formed without distortion.

During the blank forming step, a printed layer 15 is formed on the side of the blank opposite to the score line forming area side to provide information about items to be contained in the box 1 in a manner recognizable from the score line forming area side (outer surface of the formed box 1). Cutting work on the printed layer 15 should be avoided as much as possible. Since the printed layer 15 is on the side of the blank opposite to the score line forming area 8 side, score lines 7 are not formed directly on the printed layer 15. When the blank 3 is made of polyethylene terephthalate (PET), the blank 3 is easy to handle and easy to form score lines 7 thereon.

The blank 3 for forming the cigarette package 1 has the following configuration:

The blank 3 comprises a main section 19 for forming the container 2, extending in one direction (bottom-to-top direction in FIG. 3), and a sub-section 20 for forming the lid 6, connected to an edge of the main section 19 which is to form the hinge 4. The main section 19 includes a front main panel 21, a bottom panel 22 and a rear main panel 23 for forming a front wall 21 a, a bottom wall (not shown) and a rear wall 23 a of the container 2, aligned in the aforementioned direction and delimited by transverse fold lines 5. Further, outer and inner side main flaps 25, 26 for forming an outer and an inner layer of each side wall of the container 2 are connected to either side of the front main panel 21 and of the rear main panel 23. The main flaps 25, 26 are connected to their associated main panels 21, 23 by a score line forming area 8. To each inner side main flap 26 is connected an inner bottom flap 33 by a transverse fold line 5. The inner bottom flaps 33 are members for reinforcing the bottom panel 22, and form an inner layer of the bottom wall of the container 2.

The sub-section 20 includes a rear sub-panel 27, a top panel 28 and a front sub-panel 29 for forming a rear wall 27 a, a top wall 28 a and a front wall 29 a of the lid 6, aligned in the aforementioned direction and delimited by transverse fold lines 5. Inner and outer side sub-flaps 30, 31 for forming an inner and an outer layer of each side wall of the lid 6 are connected to either side of the rear sub-panel 27 and of the front sub-panel 29. The sub-flaps 30, 31 are connected to their associated sub-panels 27, 29 by a score line forming area 8. To each inner side sub-flap 30 is connected an inner top flap 32 by a transverse fold line 5. The inner top flaps 32 are members for reinforcing the top panel 28, and form an inner layer of the top wall of the lid 6.

The score line forming area 8 is thus provided between the front main panel 21 and the outer side main flap 25, between the rear main panel 23 and the inner side main flap 26, between the rear sub-panel 27 and the inner side sub-flap 30, and between the front sub-panel 29 and the outer side sub-flap 31, each, so that the longitudinal edges of the box 1 are all formed from the score line forming areas 8. The score lines 7 are formed in each score line forming area 8 as described above, and the resulting score-lined areas are each bent into a rounded edge. As a result, the box 1 has longitudinal edges 16, 18 each formed as a rounded edge.

After the score line forming step, the blank is formed into the box 1 by folding the blank with the surface with score lines 7 outside, where each score line forming area 8 is bent utilizing the score lines 7 so that the resulting cigarette package 1 has rounded edges 16, 18. The package 1 with the rounded edges is easy to hold and fits comfortably in the hand. While FIGS. 1 and 2 show a hinged lid package to which the present invention is applied, the present invention is applicable to a tongue lid package in a similar manner.

As shown in FIG. 6, taking into consideration the restoring force opposing the bending when the blank 3 is formed into the box 1 by folding or bending, the score line forming areas 8 may include non-forming parts 34 in which the score lines 7 are not formed. For example, the score line forming area 8 provided between the rear main panel 23 and each inner side main flap 26 may include a triangular non-forming part 34 a at the bottom panel 22-side end. The score line forming area 8 provided between the rear sub-panel 27 and each inner side sub-flap 30 may include a triangular non-forming part 34 b at the top panel 28-side end, for example. The score line forming area 8 provided between the front main panel 21 and each outer side main flap 25 may include a rectangular non-forming part 34 c at the bottom panel 22-side end, for example.

As shown in FIG. 7, the score line forming method according to the present invention is applied also to the inner frame 10. Specifically, a score line forming area 8 is provided between the main panel 17 and each flap 35, and score lines 7 are formed in each score line forming area 8 in the same way as described with respect to the blank 3. As a result, the inner frame 10 has rounded edges 24.

EXPLANATION OF REFERENCE SIGNS

-   1 Cigarette package (box) -   2 Container -   3 Blank -   4 Hinge -   5 Transverse fold line -   6 Lid -   7 Score lines -   8 Score line forming area -   9 Groove -   10 Inner frame -   11 Cutting device -   12 Top opening -   13 Blade -   14 Access opening -   15 Printed layer -   16 Rounded edge -   17 Main panel -   18 Rounded edge -   19 Main section -   20 Sub-section -   21 Front panel -   22 Bottom panel -   23 Rear panel -   24 Rounded edge -   25 Outer side flap -   26 Inner side flap -   27 Front sub-panel -   28 Top panel -   29 Rear sub-panel -   30 Inner side sub-flap -   31 Outer side sub-flap -   32 Inner top flap -   33 Inner bottom flap -   34 Non-forming part -   35 Flap 

1. A method of forming score lines on a blank, comprising steps of: forming a sheet-shaped resin blank able to be formed into a box by folding, and forming score lines in score line forming areas of said blank which are to be bent to form outer edges of the box, to extend in a direction in which the outer edges should extend, wherein in said score line forming step, said score lines are formed in a manner causing grooves to be produced on a back side of each score line forming area, parallel to said score lines, through plastic deformation.
 2. The method according to claim 1, wherein the grooves are formed along the respective score lines in a manner corresponding to the respective score lines.
 3. The method according to claim 1, wherein the box to be formed comprises a box-shaped container open at the top and a box-shaped lid connected to a top edge of the container functioning as a hinge to open and close the container, said blank comprises a main section for forming the container, extending in one direction, and a sub-section for forming the lid, connected to an edge of the main section which is to form the hinge, the main section includes a front main panel, a bottom panel and a rear main panel for forming a front wall, a bottom wall and a rear wall of the container, aligned in the direction and delimited by transverse fold lines, and outer and inner side main flaps for forming an outer and an inner layer of each side wall of the container, connected to either side of the front main panel and of the rear main panel, the sub-section includes a rear sub-panel, a top panel and a front sub-panel for forming a rear wall, a top wall and a front wall of the lid, aligned in the direction and delimited by transverse fold lines, and inner and outer side sub-flaps for forming an inner and an outer layer of each side wall of the lid, connected to either side of the rear sub-panel and of the front sub-panel, and said score line forming areas are provided between the front main panel and the outer side main flap, between the rear main panel and the inner side main flap, between the rear sub-panel and the inner side sub-flap, and between the front sub-panel and the outer side sub-flap, respectively.
 4. The method according to claim 1, wherein in said blank forming step, a printed layer for providing information about items to be contained in the box in a manner recognizable from the score line forming area side is formed on a side of said blank opposite to said score line forming area side.
 5. The method according to claim 1, wherein said blank is made of polyethylene terephthalate.
 6. A method of manufacturing a package using the score line forming method according to claim 1, wherein after said score line forming step, said blank is formed into the box by folding and bending said blank with the score-lined surface outside.
 7. A package with rounded edges manufactured by the package manufacturing method according to claim
 5. 